Luke 19: 1-10
The True Seeker
St. Luke describes Zacchaeus as one who "was seeking to see who Jesus was." As a resourceful person, he does all the could to fulfill his plan.
But it's not the physical obstacles alone that Zacchaeus overcomes in his seeking by running ahead and climbing a tree. He, a man of social status and authority, should never be running and climbing trees in public. In his seeking, he is willing to make himself the crowd's laughing stock.  He overcomes people's opinion and his pride to see Jesus.
In addition, Zacchaeus is willing to give away half of his wealth and to make up for any injustice he might have committed. Here, it is significant to note that he uses a conditional phrase, "if I have extorted (other translations use "cheated") anything from anyone." Does that mean he never cheats anyone intentionally? Whatever the case might be, he is seriously seeking not only to see Jesus, but to respond to Jesus' call to conversion.
Zacchaeus is a seeker.
However, it is Jesus, the Savior, who "has come to seek and to save" people like Zacchaeus. In fact, it is in God's plan of salvation of the whole human race that Jesus has come. As he tells Zacchaeus, "Today, I must stay at your house." There is a sense of a plan designed by God being accomplished here. (The same verb must is used by Luke elsewhere for the same theological point throughout his gospel, for example, Jesus' response to Joseph and Mary when they found him in the Temple at the age of 12 in 2:49, or in his prediction of his passion and death to the disciples in 9:22). 
Jesus is the true seeker.
So, it is important for us to seek and to overcome the various obstacles to find God in our lives. It is more important, however, to know that Jesus is the true seeker from God who "has come to seek and save what was lost."
 Luke Timothy Johnson, The Gospel of Luke. Sacra Pagina Series. Collegeville, MN: Liturgical Press, 1991; p. 285.